Peter has $400 and John has $220. They went to a store and spend the same exact amount. Peter has 4 times John's money left. How much did they spend?

Question

I know the answer would be 240 and 60 but I need the formula and equation to come up with the answer. Thank u in advance!

Answer 1

Let x = the amount that Peter and John each spent.

 

(Peter has left)                        =                 4  *  (John has left)

    $400 - x                             =                 4 * ($220  - x)

 

   400 - x = 880 - 4x

    3x = 480

      x = 160         [They each spent $160]

 

Peter has $400 - $160 = $240 left.

John has $220 - $160 = $60 left.